Method for surface ornamentation for thermal plastic articles



Jan. 30, 1945. N. BARBIERI 2,368,085

METHOD FOR SURFACE ORNAMENTATION FOR THERML' PLASTIC ARTICLES Filed Dec. 17, 1943 ENTOR ATI'ORN EYS Patented' Jan.. Si??? w45 METHOD FOB SURFACE ORNAMENTATION FOR THERMAL PLASTIC ARTICLES Nicholas Barbieri, Providence, R.. I., assg'nor to Uncas Manufacturing- Company, a corporation oi Rhode Island Application December 17, 1943, Serial No. 514,726

l Claim.

rlhis invention is :for a method for surface ornamentation for thermal plastic articles and for manufacturing ornamental thermal plastic articles.

An object oi the invention is to provide a simple and eiiective process for surface ornamentation for 'thermal plastic articles.

Another object of the invention is to provide a process for surface ornamentation for thermal plastic articles that may be carried out by machine processes.

Another object of the invention is to provide a process for surface ornamentation of thermal plastic articles in which the ornamentation will substantially resemble in appearance that provided by engraving or provided. hy an etching process on glass.

Another object is to provide a new process for manufacturing thermal plastic ornaments.

With these and other objects in View the invention consists oi certain novel features as will be more fullydescribed and particularly pointed out in the appended claims.

the accompanying drawing: A

i is a perspective view oi an oven suitable for carrying out. one of the steps oi the invention;

2 is sectional view a die suitable for performing another step oi the invention;

Fig. 3 is view similar to that shown? in Fig. 2 but with the die closed upon the article to be decorated;

illustrates the' article in perspective, showing surface deformations as produced lov the die;

Fig. 5 illustrates a further step in the vprocess of the instant embodiment of the invention;

Fig. 6 is a sectional view of the article acted upon subsequent to the operation performed by the device shown in Fig. 5; Y

Fig. 7 illustrates in perspective the article shown in Fig. 6;

Fig. 8 illustrates another step in the process;

Fig. g is a sectional view showing the article with surface. deformations in the inverse order as that shown in Figs. 3 and 4;

Fig. 10 is a perspective view of the article with the finished ornamented surface;

Fig. 11 is a sectional view on an enlarged scale and taken substantially on line I I-Il ot Fig. 10

Fig. 12 is a view similar to that shown in Fig. 11 and with colored material added to the walls of the cavity;

Fiss. 13 and 14 illustrate two different articles made in accordance with scribed.

I have discovered that certain thermal plastic materials in sheet form when sufficiently softhe process herein detened by heat, then deformed under force into a different shape and permitted to set in such deformed condition will substantially recover nitial size and shape when subsequently reheated.

In accordance with the invention the thermal plastic article having the above properties is rst h ated to a sufcient degree to soften the same te be 'readily compressed to receive the chosen design. The article while in the softened condition is acted upon with suitable devices so as to substantially compress the material about the portion thereof forming the design. This will provide a portion oi material raised above the surface of the surrounding material in the form of the design desired and in which relatively little or no compression force has been applied.

The article is then permitted to cool and set in such .deformed condition. Next about seventyfve per cent oi the raised portion of the design is removed by any convenient manner such for example as by grinding.

The article is next reheated to about the same temperature `as that used for softening which will cause the compressed portier ai the material to recover size',` that is it will spring back to substantially its origina-l thickness. There will be in this recovered surface recesses or cavities of a depth substantially that of the thickness of ma terial removed and of forms corresponding to the shape of the raised portions prior to being removed.

When a clear transparent thermal plastic ar- Jticle is to be decorated the design may be applied on the rear surface of the article. The raised portion of the material is removed by grinding which will provide the remaining portion of this raised material with 'a ne abraided, surface. In the completed decoration this abraided sur-1 face when viewed through the material will have a beautiful so-called frosted appearance.

If desired gold foil, silver foil, paints, and/or the like maybe inlaid in the recesses or cavities to thereby intensity the decorative effect of the design.

Referring to the drawing for a more detailed description of the invention and'in which drawing I have illustrated one method of practicing the invention, I0 shows an oven which may be of any of the approved manufactureand which may be heated to about 275 to 300 Fahrenheit. In this oven is placed a strip I0 of thermal plastic sheet material I I. A thermal plastic material in the form of sheet stock in the synthetic resin group which has been found suitable for this invention is that known as Lucite," which is a methyl methacrylate. This material I find preferable in many instances because of its freedom of all color and clear transparency.

Another plastic in sheet form which has been found suitable is that known in the art of plastics as Plastacele, which is a cellulose acetate.

After'the strip II has been heated to soften the same sufficiently to readily have the design impressed thereon, it is positioned between the parts I2--I3 of a suitable die. The upper part I2 of the die has in its surface suitable cavities 'I4 therein forming the design to appear in the nished article.' The parts of the die are moved towards each other and force is applied to compress all of the material between the parts of the die suciently'so as to fill all of the cavities of the die part I2. The strip is held between the die parts until set in thisl deformed condition. It will be understood that the portion of the strip I I directly beneath the cavities in the die part I2 will'have been compressed only suilicient to ll the cavities and conform to the shape thereof.

After the strip II has sufficiently cooled and set in the deformed condition it is removed from between the die parts. The portion I5 thereof will, as best seen in Fig. 4, be of substantially less thickness than the original size and the thickness ofthe sheet I I at the raised portion I6 forming the design will be-substantially of the same initial thickness. 'Ihe strip II is next positioned on the table I1 of a suitable grinding device and the grinding disk IB set to remove about seventyve per cent of the raised portion. I6. Although I prefer to remove about seventy-five per cent of the raised portion, this is not critical and the entire raised yportion may be removed and even part of the material of the portion I 5 may be removed. The amount of material removed is conditional upon the results desired.

Employing a grinding process for removing part of the raised portion I6 will provide the surface I8 on the remaining portion I6' of the portion I 6 with fine abrasions thereon which will give the decoration a so-called frosted surface seen in a cut glass design and that provided by an etching process.

The strip II is next returned to the oven I0 and reheated to a degree suflicient for the thermal material to recover initial size. This recovered surface will now have cavities I9 therein conforming substantially in depth and in form to the cavities I4 in the die part l2. The walls of the cavities I9 will have a frosted surface 20. In some instances it may be desired to color the walls of the cavities and Jfoil, paint, and/or the like material 2I may be inlaid and secured to the wall by adhesion or any other manner known in the art.

The strip is now cut to the desired shape which may take the form of a brooch shown in Fig. 13. It may be made into a picture frame as shown in Fig. 14.. I may in some instances apply an appropriate design to the plastic strip and subsequently form the same into a jewel such as a cameo.

I have shown and described an oven as a means Aof heating the plastic article or strip material to soften the same. However, the plastic material may be heated in various other ways. The die itself may have a heating 'unit incorporated therein in a manner well known in the plastic art. A die has been shown for impressing the design into the strip material. However, it can be readily conceived that the strip material may be passed between rollers the surface of which may have the desired design.

It will be apparent that a translucent or opaque thermal plastic material or one that is colored may be employed in carrying out the invention. When an opaque material is chosen the design should be placed on the front surface of the article.

I claim:

The method of decorating thermal transparent plastic articles which consists in applying suilicient heat to the article to soften the same and while in softened condition impressing a design in relief on the article and then permitting the article to cool to set, in such deformed condition, then removing by grinding part A of the raised portion of the stock and subsequently subjecting the article to sufiicient heat to cause the deformed part of the article to recover its initial size and form.

NICHOLAS BARBIERI. 

